The invention relates to an anamorphotic optical system transmitting an image while deforming it in one direction and leaving it undeformed in a substantially perpendicular direction. The invention also relates to an anamorphotic/deanamorphotic arrangement.
An optical system of this type is known from the document FR 2,537,295 in which an infrared anamorphotic arrangement is described. It comprises two prisms arranged in such a way that an image is deformed in only one direction X and is not subjected to a deformation in the other direction Y. Thus, an object having a square format is observed as a rectangular format, while one of the dimensions remains unchanged.
Referring to the co-ordinates in the two directions X and Y as x.sub.1 and x.sub.2 and y.sub.1 and y.sub.2, respectively, for the object (x.sub.1, y.sub.1) and the image (x.sub.2, y.sub.2), the following equations hold: EQU x.sub.1 =kx.sub.2 and y.sub.1 =y.sub.2.
The coefficient k is a constant for this type of anamorphotic arrangement. It thus deforms the obtained image in a uniform manner.
For certain applications it is necessary to have an anamorphotic arrangement in which k is not a constant and which may have different values throughout the range of co-ordinates x.sub.1 of the image.
The technical problem is to have an amorphotic optical system in which the coefficient k is not constant throughout the image in the direction of deformation.